Tensile Force Generating Device with Segmented Guide Pipe
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Solution Overview
Problem
Existing motion assist devices for elderly individuals face challenges in maintaining a compact size while allowing smooth expansion and contraction of elastic members, and in generating tensile force in accordance with bending angles of lower limbs without hindering motion.
Innovation Solution
A tensile force generating device with a guide pipe and tubular elastic member configuration that prevents contact between the elastic member and guide pipe during compression, allowing for compact design and smooth expansion and contraction, and a slider mechanism that eliminates slack in the tensile force transmitting member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a guide tube is fitted over the elastic structure to prevent abnormal bending, then the elastic structure is protected from curving, but the device size increases due to the need for large clearance
Solution Approach 1:
The guide tube is divided into two functional sections: a first guide tube section with a smaller inner diameter that contacts the elastic structure to prevent curving, and a second guide tube section with a larger inner diameter that provides clearance to accommodate bulging during compression. This segmentation allows the device to maintain both protective guidance and compact size.
2Volume of stationary object
If the elastic structure is allowed to curve during compression, then the device size can be reduced, but smooth expansion and contraction are hindered by friction against the guide tube
Solution Approach 1:
Different sections of the guide tube are given different inner diameters to serve different functions. The first section has a smaller diameter for contact and guidance, while the second section has a larger diameter for clearance and smooth motion. This local quality differentiation resolves the contradiction between compact size and smooth operation.
3Ease of operation
If large clearance is secured between the guide tube and elastic structure, then smooth motion is maintained, but the device becomes larger and heavier
Solution Approach 1:
The guide tube is segmented into two sections with different inner diameters. The first section minimizes clearance to reduce size and weight, while the second section provides sufficient clearance for smooth motion. This segmentation allows the device to achieve both compact weight and smooth operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables a compact motion assist device that generates tensile force in accordance with bending angles, enhancing the assistive capability for bending and stretching motions while maintaining a lightweight and compact structure.
Implementation Method 1
an elastic force is generated by compression of the elastic bodies
Data Source
AI summary
A tensile force generating device includes: a base member; a guide pipe having a base end fixed to the base member and a free end, the guide pipe being provided with a first slot extending in a longitudinal direction; a tubular elastic member fitted over the guide pipe and having a base end supported by the base member on a side of the base end of the guide pipe; a flexible wire passed into the guide pipe from a side of the base end of the guide pipe; an end member slidably mounted on the guide pipe and supporting a free end of the elastic member; and a slider slidably received in the guide pipe, joined to a tip of the wire, and joined to the end member through the first slot.